Jet engines and power generating turbines are moving toward increasingly efficient designs that necessitate higher operating temperatures. Refractory multi-principle element alloys (RMPEAs), also called refractory high entropy alloys (RHEAs), or refractory complex concentrated alloys (RCCAs), maintain strength to significantly higher temperatures than traditional superalloys, which are pushed to the limits of engineering in current generation engines [1]. In this work, we compare the high temperature (800-1250˚C) mechanical properties (Fig.1(c)) and microstructures of alloys that are modeled to have slip controlled by different dislocation types (edge vs screw) [2-3], specifically: pure W, equiatomic MoNbTaVW, and two non-equiatomic CrMoNbV alloys. Additionally, we discuss differences in the high temperature properties and microstructures between the homogenized and as-cast materials (Fig.1(a-b)), and the types of heat treatment necessary to produce a homogeneous chemical distribution in RMPEAs containing high melting point elements.This work was performed under the auspices of the United States Department of Energy by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52-07NA27344 and was supported by the Laboratory Directed Research and Development (LDRD) program under project tracking code 22-SI-007.